Self-generating pressure device for infusion administration systems



March 6, 1962 H. c. BARON SELF-GENERATING PRESSURE DEVICE FOR INFUSIONADMINISTRATION SYSTEMS Flled March 4, 1959 m m m m HOWARD C. BARON FIG.4. Y

United States Patent 3,023,750 SELF-GENERATING PRESSURE DEVICE FOR IN-FUSION ADMINISTRATION SYSTEMS Howard C. Baron, 36 E. 36th St., New YerN.Y. Filed Mar. 4, 1959, Ser. No. 797,194 6 Claims. (Cl. 128-214) Thisinvention relates to improvements in apparatus for intravenous infusionor transfusion, and in particular relates to a new and improvedpressure-operated assembly for the infusion of blood or plasma to apatient requiring the same.

At the present time several conventional methods are employed forinfusing blood or other fluids into the blood stream. The most commonmethod is to hang a glass jar or plastic bag containing blood, bloodplasma or the like on an infusion stand and allowing the fluid to flowby gravity to the veins of the patient. It is also known to employ handpumps which are attached directly to the infusion bottle, these pumpsrequiring constant or intermittent manual manipulation and consequentlyan attendant present to operate the same. It is also known to employmechanical pumps which are attached to the infusion bottle and result inthe blood being fed under pressure to the patient. The mechanical pumpsalso require manual control and in addition must include a power sourcefor the operation thereof. Most recently, the use of flexible plasticinfusion containers has become prevalent, such infusion containers beingcapable of being manually squeezed by an attendant for the feeding ofthe contents under pressure to the patient.

All of the above conventional methods are subject to inherentdisadvantages which limit the use thereof to particular applications.For example, the gravity flow method, which at the present time is ingeneral use, requires a cumbersome infusion stand for purposes ofelevating the infusion bottles at least several feet above the level ofthe patient. The rate of flow is then determined by :the diameter of theinfusion needle, the height of the infusion bottle, and the intravenouspressure. The intravenous administration of fluid by hand pumps requiresthe constant cr intermittent presence of an attendant to maintain thepressure in the infusion bottle and prevent any possible massive airembolus at the conclusion of the infusion operation. The use ofmechanical pumps minimizes the necessity of constant supervision by anattendant, but in this instance, the pumps are bulky and heavy andrequire a power source for their operation. Thus, they are not usuallytransportable and are not commercially practical for mass use due to thehigh cost of each individual unit. The present method of use of flexibleplastic infusion containers requires the container to be suspended froman infusion stand for normal gravity flow operation, or in thealternative requires the container to be manually manipulated.

It will be appreciated that in places where mass transfusions arerequired in large numbers, such as on the battlefield or in disasterareas, it is often essential to pro vide a controlled flow of blood orplasma expanders in a large member of simultaneous transfusions, but thenature of the situation as such that it is impossible to'provide anattendant for each transfusion case. In addition, it is impossible toprovide mechanical pumps or the like with each transfusion unit, andeven if the provision of such pumps were possible, a power source forsaid pumps would not be readily available. In addition, it may bementioned that the gravity flow method of infusion is often impossibleto follow under battlefield conditions since the use of upright infusionstands or supports provides a ready target.

In accordance with the present invention, there is provided aself-contained infusion pump for feeding the 3,023,750 Patented Mar. 6,1962 intravenous fluid to a patient under a steady pressure, theinfusion pump being in the nature of an expandible bag or envelopecontained within the infusion container and having means for filling theexpandible bag or envelope with gas in such a manner as to expand thebag within the container and force the intravenous fluid out of thecontainer. In the preferred form of the invention, the expandible hagcontains chemical ingredients which, when mixed, generate a gas whichfills the bag and causes the latter to expand.

An object of the present invention is the provision of pressure-operatedinfusion assembly of the character described which will provide a steadyflow of intravenous fluid to the patient under a steady pressure andwith a minimum of manual attendance, and which can also be used, whendesired, in the usual manner for gravity-flow administration.

Another object of the present invention is to provide apressure-operated infusion assembly of the character described which isof small, compact size, is light in weight,

. and is inexpensive in manufacture, so that it may be economicallyprovided in quantity for mass use.

Still another object of the present invention is to provide apressure-operated infusion assembly of the character described whichacts automatically to prevent air embolus, and at the same time acts asa check valve at the conclusion of the infusion.

Additional objects and advantages of the present invention will becomeapparent during the course of the following specification when taken inconnection with the accompanying drawings illustrating preferredembodiments thereof, and in which:

FIG. 1 is a plan view of an infusion container shown in invertedposition and incorporating a flexible bag in accordance with theinvention, portions of the container and bag being broken away to revealinner constructional details;

FIG. 2 is a section taken along line 22 of FIG. 1;

FIG. 3 is a sectional view corresponding to FIG. 2, but showing theflexible bag in an expanded position, and also showing a portion of theadministration assembly connected to the container;

FIG. 4 is a plan view of an infusion container incorporating a modifiedform of the invention; and

FIG. 5 is a perspective view of the administration assembly used withthe infusion containers.

While the self-generating pressure system of the instant invention maybe applied to any type of infusion container, for purposes ofillustration there is shown in the drawings the well-known type offlexible container having walls made of a soft and bendable plastic.This container communicates with a feeding tube which terminates in ahollow needle for injection into the patients blood stream.

Referring in detail to the drawings, there is shown in FIG. 1, by way ofexample, an infusion fluid container of the conventional and well-knownflexible type in the nature of a pliable plastic bag made of transparentpolyvinyl chloride or the like. The container 10 is completely sealed,as by marginal heat sealing 12 at its top and bottom ends, except for anopen neck portion formed by a hollow tube 14 which is open at its endsand is sealed in a position extending through the bottom wall of thecontainer 10. The outer end of the tube 14 is closed off by a softrubber cap 16 having a bottom wall 18 and a peripheral flange 29 whichencircles and grasps the lower end of the hollow tube 14.

The container 10 is partially filled with a measured amount of infusionfluid 22 to be administered, the fluid being, for example blood plasma,blood mixed with an anti-coagulant, etc. Prior to the sealing of thecontainer 10, the air therein is wholly evacuated, so that a vacuum iscreated in the space above the fluid 22.

A flexible infusion fluid container such as the container isconventionally provided with an-administration assembly which is used totransfer the fluid in the container to the patient requiring such fluid.Such an administration assembly 24 includes a flexible tube 26, normallymade of a transparent plastic, to one end of which a hollow needle 28 isafiixed, and to the other end of which a longer hollow needle 30 isaffixed.

The needle 28 is sized to puncture the bottom wall 18 of the tube cap 16and to extend upwardly through the tube 14, in the manner shown in FIG.3, with the hollow interior of the needle 28 in communication with thefluid 22 within the container 10. The fluid thus may flow through thehollow needle 28 and through the flexible tube 26. As is conventional, ametal disc or flange 32 may be affixed at the base of the needle 28 toserve as stop means to prevent the needle 28 from being inserted' toofar within the tube 14.

The flexible container 10 is conventionally provided with an aperture orslot 34 in the heat-sealed marginal area 12 opposite the neck 14, bymeans of which the container may be hung in an inverted position from aninfusion stand or other support. When the needle 28 is inserted throughthe cap wall 18 into the hollow tube 14 and the other needle 30 isinserted into a vein of the patient, the fluid 22 within the container19 is fed by gravity through the tube 26 to the patient. In those caseswhere the patient requires a pressure feed of the fluid, it is customaryto provide an attendant to manual- 1y squeeze the flexible container 10in order to force the fluid from the container. A pinch clamp 36 mayalso be mounted on the flexible pipe 26 to control the flow of fluidtherethrough.

The apparatus thus far described is conventional and well-known, andprovides an inexpensive and easily portable assembly for storing andadministering blood and other intravenous fluids. The invention hereinresides in self-expanding means placed within the container for creatinga pressure Within the container whereby the fluid therein is forced outand through the flexible tube 26 in a steady, positive flow withoutrelying on gravity, as is usual.

In accordance with the invention, there is provided a small expandiblebag within the container 10, the bag containing a supply of gas orcontaining means for generating gas. The bag thus continually expandsduring use of the infusion apparatus, forcing the liquid under pressureout of the container. The gas generating means may be in the form of asmall container of compressed gas which can be ruptured or otherwiseopened to re lease the gas within the expandible bag. Preferably,however, the gas generating means is in the form of two or more chemicalagents which may be mixed or dissolved in a liquid to generate the gas.

FIGS. 1 and 2 illustrate one example of the preferred gas generatingmeans. In these views, a small flexible and resilient bag 40 is locatedwithin the container 10. The bag 40 may be made of soft rubber or aplastic which is capable of stretching, and is in the form of a hollowenvelope which is completely sealed around all of its edges.

The bag 40 contains a capsule or ampule 42 which is capable of beingcrushed or ruptured from the exterior of the container 10. 'For thispurpose, the member 42 may be a thin-walled glass ampule or may be aconventional medicinal capsule, both of which may be crushed bysqueezing through the flexible walls of the container 10 and of the bag40-. The capsule or ampule 40 may contain a liquid or chemical, while anadditional chemical (in FIG. 1 being shown as a powder 44), is containedwithin the bag 40 outside the ampule or capsule' 42. The chemical agentsare such that upon mixing they will generate gas to cause the bag 40 toexpand in size.

The aforementioned chemical agents may be any suitable ingredients whichwill generate gas when mixed or when dissolved in water; there being alarge number of well-known materials suitable for this purpose. Forexample, the powdered chemical 44 within the bag 40 may be a measuredamount of dry, baking soda, while the capsule 42 may contain water. Whenthe capsule 42 is broken, the water will mix the baking soda, generatingcarbon dioxide gas. As another example, the chemical ingredient 44 inthe bag 40 may be calcium carbonate and the capsule 42 may containdilute hydrochlon'c acid.

The bag 46 may be secured within the container 10 or may be looselycontained therein. When the capsule or ampule 42 is ruptured or crushed,the material therein will mix with the chemical agent 44, generating gaswhich will cause the walls of the bag 49 to stretch and the bag 40 toexpand until it fills the interior of the container 10 above theinfusion fluid 22. When the bag 40 expands sufliciently to pressdownwardly upon the infusion fillld 22, it exerts a positive pressureupon the fluid, forcing the fluid out through the tube 14, the hollowneedle 28 and the flexible tube 26, to the vein of the patient.

The use of the expandible bag 40 eliminates the danger of an air embolusalmost completely. In the final stages of the infusion, the bag 44expands until it completely .fills the interior of the container 10, asshown in FIG. 3.

The outlet tube 14 is therefore completely sealed oif when the last ofthe infusion fluid 22 leaves the container 10, and there is nopossibility for air within the system to be fed to the veins of thepatient. At the same time, the fully-ex anded bag 48 acts as a checkvalve in sealing off the outlet tube 14, preventing the return of bloodor infusion fluid to the container.

In conventional transfusion arrangements of the type shown herein, theoutlet tube 14 is open at its top to permit the passage of infusionfluid therethrough. An exarnination of FIG. 3 will reveal that when thebag 40 is almost fully expanded, it will engage and seal off the opentop of the outlet tube 14, with the result that the container 10 will besealed off from the outlet flow of fluid before all of the intravenousfluid has been fed to the patient. As a result there is provided in theside walls of the outlet tube 14, a series of apertures 46, the bottomedges of which register with the bottom wall of the container 10, as isbest seen in FIG. 3. The apertures 46 insure that all of the containedinfusion fluid 22 is discharged from the container 10. At the same timethe apertures 46, are sealed off by the fully-expanded flexible bag 40at the completion of the transfusion operation, to prevent air embolus.

FIG. 4 illustrates an alternate manner of constructing the expandiblebag. In this view, the bag 50 is made of the same material as thecontainer 10, that is to say of a flexible plastic sheet material whichneed not be stretchable. The bag 50 is in the form of a completelysealed envelope which is of slightly larger size than the container 10.The bag 50 is sealed at its top end to the top heatsealed edge portion12' of the container 10. The free lower portion of the bag 50 is foldedup in a number of staggered folds 52, so that in the unexpandedcondition, the lower folded portion of the bag 50 is located above thelevel of the intravenous fluid 22. The bag 50 contains chemicals for therapid generation of gas, as was previously described, or contains asmall cylinder of compressed gas. When gas is generated or releasedtherein, the bag 50 will expand and unfold, forcing the intravenousliquid from the container 10', until the bag 50 entirely fills theinterior of the container and its bottom end seals off the outlet tube14.

It is to be understood that the expandible bag may also be used within acontainer of the glass bottle type also commonly used for bloodinfusion. In this instance, the

expandible bag could be pre-filled with suflicient compressed air orother gas to permit the bag to expand to an extent to fill the interiorof the bottle after the intravenous fluid has been fed to the patient.In the event that an expandible bag containing a capsule or ampule isused Within a glass bottle, the capsule or ampule can be broken by meansof a needle puncture through a rubber stopper, to permit mixing of thechemical agents.

The use of an expandible bag within the infusion container, as describedabove, presents the advantages of providing a readily transportablepressure system in which constant attendance is unnecessary. Inoperation, all that is necessary is to attach the administrationassembly 24, inject the patient, and release or generate the gas. Thesystem is entirely independent of gravity and the infusion bottle orcontainer, can be placed at body level or below. For example, thecontainer can be suspended between the legs of a patient on a litter,suspended from the patients belt, hung from the neck of a transportedpatient, etc. In hospitals it may be placed on a bed stand next to thepatient or on the anesthesia machine at the head of the operating table.No cumbersome infusion stands are re quired as in gravityadministration. Sufiicient pressure may be generated to overcome thevenous pressure of the patient, and, if necessary, the systolic bloodpressure of the patient where intra-arterial transfusions are required.With the assembly of the invention, as many transfusions may be given asare needed without depleting the available manpower in a mass emergencyor even in routine hospital Work.

While preferred embodiments of the invention have been shown anddescribed herein, it is obvious that numerous omissions, changes, andadditions may be made in such embodiments without departing from thespirit and scope of the invention.

What I claim is:

1. Infusion apparatus comprising a flexible-walled container for storinga supply of fluid to be fed intravenously and having a fluid outletopening, an expandible bag within said container, said bag beingcompletely sealed and having a normal collapsed position in which itoccupies a portion of the container, and means within said bag forgenerating a supply of gas therein in sufficient volume to cause saidbag to expand to an extended position in which it substantially fillsthe interior of said container, said gas-generating means comprising aplurality of chemical ingredients capable of generating gas when mixed,and a frangible member normally separating said chemical ingredients,said frangible member being accessible from the exterior of saidcontainer through the flexible walls of the latter, whereby thefrangible member may be selectively and manually ruptured to mix saidchemical ingredients.

2. Infusion apparatus according to claim 1 in which said frangiblemember comprises a capsule containing one of said chemical ingredients.

3. Infusion apparatus according to claim 1 in which said expandible bagcomprises an envelope having stretchable walls.

4. Infusion apparatus according to claim 1 in which said expandible bagcomprises an envelope of an expanded size at least equal to the internalvolume of said container said envelope being normally folded to occupyonly a portion of said container.

5. Infusion apparatus comprising a flexible container having a fluidoutlet opening, a completely sealed expandible bag within saidcontainer, and chemical means within said bag for generating a supply ofgas to expand said bag to substantially fill said container, saidchemical means comprising a plurality of chemical ingredients capable ofgenerating gas when mixed, and a frangible member normally separatingsaid chemical ingredients, said frangible member being selectively andmanually ruptured to mix said chemical ingredients.

6. Infusion apparatus comprising a flexible container for storing asupply of fluid to be fed intravenously and having a fluid outletopening, an expandible bag contained within said container, said bagbeing completely sealed and having a normal collapsed position in whichit occupies a portion of the container, and means including a frangiblemember within said bag for generating a supply of gas therein insuflicient volume to cause said bag to expand to an extended position inwhich it substantially fills the interior of said container so that saidbag in expanding acts to exert pressure upon said fluid to force thelatter out of the container, said frangible member being selectively andmanually ruptured through said flexible container and through saidexpandible bag manually from outwardly of said container.

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